Dexamethasone is a synthetic glucocorticoid, which may cause perineal irritation when given intravenously. The major clinical manifestations are pruritus and pain，and the incidence vary between 38%-71%. Some patients undergo spontaneous remission, while others develop into severe pain or pruritus. Dezocine, a new synthetic opiate agonist-antagonist, has been used for the treatment of pain and pruritus, but its role in relieving dexamethasone induced perineal irritation has not been studied yet. The aim of this study was to investigate the efficacy of dezocine pretreatment on dexamethasone induced perineal irritation.